Simplify the following expression: $r = \dfrac{q^2 + 5q - 50}{q + 10} $
Explanation: First factor the polynomial in the numerator. $ q^2 + 5q - 50 = (q + 10)(q - 5) $ So we can rewrite the expression as: $r = \dfrac{(q + 10)(q - 5)}{q + 10} $ We can divide the numerator and denominator by $(q + 10)$ on condition that $q \neq -10$ Therefore $r = q - 5; q \neq -10$